To give an estimate of the total number, , of seats of the social democratic party in all the municipal councils in a country, the population was stratified into four strata using the total number of seats in every council. We find information on these strata below :

# seats Ni Ex Yk,i (pop) ExY2 (pop) Ek yk,i Sample Ek yki Sample 31 - 40 44 756 13784 89 1647 41 - 50 168 3383 72223 441 9735 51 - 70 56 1545 44529 250 8294 71+ 16 617 24137 102 5294